Dry separation method using high-speed particle beam

ABSTRACT

A dry separation method is a dry separation method for ashing a photoresist, including a spraying and separating step of spraying sublimation particles on the photoresist and separating the photoresist. A dry separation apparatus is a dry separation apparatus for ashing a photoresist, including a nozzle for generating a high-speed particle beam that includes sublimation particles. The nozzle generates ultra-high speed uniform nanoparticles by passing therethrough a particle generation gas including carbon dioxide, and includes an expanding portion having a shape so that the cross sectional area thereof becomes wider toward a discharge side of the nozzle. The expanding portion sequentially includes a first expanding portion and a second expanding portion, and an average expansion angle of the second expanding portion is bigger than an expansion angle of the first expanding portion.

TECHNICAL FIELD

The present invention relates to a dry separation apparatus, a nozzlefor generating a high-speed particle beam for dry separation and a dryseparation method using the high-speed particle beam, and morespecifically, to a dry separation apparatus for removing a photoresistcoated on the surface of a wafer by injecting sublimation high-speedparticles for a process such as photolithography or the like performedin a process of manufacturing a semiconductor substrate, a nozzle forgenerating a high-speed particle beam for dry separation and a dryseparation method using the high-speed particle beam.

BACKGROUND ART

A semiconductor element is generally manufactured by forming a patternon a wafer through a photolithography process. More specifically, thesemiconductor element is manufactured by forming a photoresist film on awafer, forming a photoresist pattern by exposing and developing thephotoresist film, and etching a silicon film formed on the wafer usingthe photoresist pattern.

For the photolithography process performed in the semiconductormanufacturing process, the surface of the wafer is etched after aphotoresist is coated. A process of removing the photoresist remainingafter the etching process is referred to as an ashing process, andremoval of the remaining photoresist is mostly accomplished in achemical method.

If the remaining photoresist is not completely removed, a problem ofgenerating an additional defect occurs in a secondary process, and thusthe ashing process is regarded as one of the most important parts in thesemiconductor manufacturing process.

A chemical wet ashing process of the prior art has a problem in that itshould diversely respond in accordance with the applicationcharacteristic of a photoresist used in a coating, and there are variousproblems as described below.

Looking into conventional techniques, Korean Laid-opened Patent No.10-2004-0098751 specifies a separation liquid which can remove amodified and hardened resist within a short time period at a high or lowtemperature by adding a separation accelerator as well as awater-soluble organic amine, a polar solvent and a corrosion inhibitor.Korean Laid-opened Patent No. 10-2006-0024478 specifies a photoresistseparation liquid composition which does not cause further corrosion ofmetal wires although an isopropyl alcohol (IPA) rinsing process isomitted and, in particular, significantly improves a separation force byapplying a photoresist separation liquid composition containing a cyclicamine, a solvent, a corrosion inhibitor and a separation accelerator.Japanese Laid-opened Patent No. JP2006072083A discloses a techniquecapable of performing separation at a room temperature on a thermallyhardened resist, as well as a general resist, by using phosphoric esterand dissolved ozone.

However, the separation solution disclosed in Korean Laid-opened PatentNo. 10-2004-0098751 falls short of an effect of suppressing corrosion ofa metal wire, and the separation solution disclosed in KoreanLaid-opened Patent No. 10-2006-0024478 does not have a sufficientseparation force for a resist created in a severe condition such as adry etching residue since a cyclic amine is used, and the separationsolution of Japanese Laid-opened Patent No. JP2006072083A isdisadvantageous in that a metal film at a lower portion is highlyprobable to be corroded due to the dissolved ozone.

Furthermore, the chemical wet ashing method inevitably uses variouschemicals and thus has fundamental problems such as environmentalproblems, maintenance cost and the like. In addition, although it hasbeen tried much to solve the problems recently as described above,performance of removing the resist still has much to be improved.

DISCLOSURE OF INVENTION Technical Problem

Therefore, the present invention has been made to solve the problems ofthe chemical wet ashing process described above, and it is an object ofthe present invention, moving away from the wet ashing process, toprovide a dry separation apparatus, a nozzle for generating a high-speedparticle beam for dry separation and a dry separation method using thehigh-speed particle beam, which can solve the problems of environmentalpollution, maintenance cost and the like and drastically improveperformance of separation by making it possible to perform a dry processof separating a photoresist by injecting sublimation solid particles.

Technical Solution

To accomplish the above object, according to one aspect of the presentinvention, there is provided a dry separation method for ashing aphotoresist, the method including an injection and separation step ofseparating the photoresist by injecting sublimation particles on thephotoresist.

According to another aspect of the present invention, there is provideda dry separation apparatus for ashing a photoresist, the apparatusincluding: a nozzle for generating a high-speed particle beam formed ofsublimation particles, in which the nozzle generates high-speed uniformnanoparticles by passing a particle generation gas formed of carbondioxide and includes a dilating portion of a shape increasing across-sectional area toward an outlet of the nozzle, in which thedilating portion is configured to sequentially include a first dilatingportion and a second dilating portion, and an average dilation angle ofthe second dilating portion is wider than a dilation angle of the firstdilating portion.

Advantageous Effects

The present invention has both economic and environmental advantages, aswell as improved processing efficiency and productivity, by using ahigh-speed particle beam injection method of a new type, getting out ofthe problem caused by the complex facilities and processing stepsaccording to existing chemical methods.

In addition, the present invention has an effect of significantlyenhancing separation (ashing) efficiency by generating sublimationparticles of a nano-size at a room temperature without a separatecooling device and, at the same time, injecting the particles at anextremely high speed.

More specifically, generation of nuclei of high number density anduniformity can be induced without a separate cooling device throughrapid expansion of a particle generation gas by providing an orifice.

In addition, sublimation particles of a nano-size can be formed bygrowing nuclei generated through a first dilating portion having agentle dilation angle, and the formed particles can be accelerated byexpanding the particles at an increased dilation angle through a seconddilating portion.

In addition, the separation (ashing) efficiency can be enhancedfurthermore by providing a third dilating portion and adjusting aseparation point, and proximity to an ashing object can be enhanced byobliquely cutting the outlet surface of the nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual view showing a process of removing a photoresistlayer formed in a wide range, as a dry separation method according to anembodiment of the present invention.

FIG. 2 is an experimental example showing a result according to FIG. 1,and FIG. 2(a) is a view showing a wafer before ashing, and FIG. 2(b) isa view showing the wafer after ashing.

FIG. 3 is a conceptual view showing a process of removing a photoresistlayer formed on a pattern after the pattern is formed, as a dryseparation method according to an embodiment of the present invention.

FIG. 4 is an experimental example showing a result according to FIG. 3,and FIG. 4(a 1), (b 1) is a view showing a wafer before ashing, and FIG.4(a 2), (b 2) is a view showing the wafer after ashing.

FIG. 5 is a conceptual view showing a process of selectively removing aphotoresist layer using a mask for etching a photoresist, as a dryseparation method according to an embodiment of the present invention.

FIG. 6 is an experimental example showing a result according to FIG. 5,and FIG. 6(a) is a view showing a wafer before ashing, and FIG. 6(b) isa view showing the wafer after ashing.

FIG. 7 is a cross-sectional view showing a nozzle for generating ahigh-speed particle beam according to an embodiment of the presentinvention.

FIG. 8 is a cross-sectional view showing a dilation angle of a dilatingportion of a nozzle for generating a high-speed particle beam accordingto an embodiment of the present invention.

FIG. 9 is a conceptual view showing a proximity relation between anozzle for generating a high-speed particle beam according to anembodiment of the present invention and an object.

FIG. 10 is a view showing major parts configuring a dry separationapparatus according to an embodiment of the present invention.

FIG. 11 is a flowchart illustrating detailed steps of a high-speedparticle beam generation step of a case using a mixture gas according toan embodiment of the present invention.

FIG. 12 is a flowchart illustrating detailed steps of a high-speedparticle beam generation step of a case using a pure particle generationgas according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereafter, specific contents for embodying the present invention will bedescribed in detail with reference to the accompanying drawings.

An embodiment of the present invention relates to a dry separationmethod, which can be largely divided into 1) a high-speed particle beamgeneration step and 2) an injection and separation step.

First, the ‘injection and separation step’ is described, and then thehigh-speed particle beam generation step will be described.

FIGS. 1, 3 and 5 are views showing embodiments of the present inventiondiversely applied in the injection and separation step, and theinjection and separation step is a dry separation method for ashing aphotoresist as shown in FIGS. 1, 3 and 5, which is a process ofseparating a photoresist by injecting sublimation particles on thephotoresist.

More specifically, FIG. 1 is a view showing an embodiment of a dryseparation method according to the present invention, which is aconceptual view showing a process of removing a photoresist 110 layerformed on the top surface of a wafer 100 in a comparatively wide range.As shown in FIG. 1, the dry separation method according to an embodimentof the present invention shows a process of separating a predeterminedarea of the photoresist 110 evenly formed on the surface of the wafer100 from the wafer 100.

Here, the photoresist 110 is directly formed on the surface of the wafer100, and the injection and separation step herein is a process ofseparating the photoresist 110 from the surface of the wafer 100.

On the other hand, FIG. 2 is an experimental example showing a resultaccording to the process of FIG. 1, and FIG. 2(a) is a view showing awafer before ashing, and FIG. 2(b) is a view showing the wafer afterashing. It can be confirmed that although the surface of the wafer 100is evenly covered with a photoresist 110 before ashing as shown in FIG.2(a), a predetermined area of the photoresist 110 is cleanly separatedafter ashing as shown in FIG. 2(b).

In addition, FIG. 3 is a view showing an embodiment of a dry separationmethod according to the present invention, which is a conceptual viewshowing a process of forming a pattern unit 120 on the top surface of awafer 100 and removing a photoresist 110 layer formed on the top surfaceof the pattern unit 120. As shown in FIG. 3, the dry separation methodaccording to an embodiment of the present invention shows a process ofseparating the photoresist 110 from the pattern unit 120 formed on thetop surface of the wafer 100.

Here, the photoresist 110 is directly formed on the surface of thepattern unit 120, and the injection and separation step herein is aprocess of separating the photoresist 110 from the surface of thepattern unit 120.

On the other hand, FIG. 4 is an experimental example, showing a resultaccording to the process of FIG. 3, and FIGS. 4(a 1) and (b 1) are viewsshowing a wafer before ashing, and FIGS. 4(a 2) and (b 2) are viewsshowing the wafer after ashing. It can be confirmed that although thesurface of the pattern unit 120 is covered with a photoresist 110 beforeashing as shown in FIGS. 4(a 1) and (b 1), the photoresist 110 isseparated and the surface of the pattern unit 120 is cleanly exposedafter ashing as shown in FIGS. 4(a 2) and (b 2).

On the other hand, FIG. 5 is a view showing an embodiment of a dryseparation method according to the present invention, which is aconceptual view showing a process of forming a pattern unit basematerial 130 on the top surface of a wafer 100 and selectively removinga photoresist 110 layer formed on the top surface of the pattern unitbase material 130.

More specifically, the photoresist 110 formed on the top surface of thepattern unit base material 130 is selectively separated by providing amask 140 on the top of the photoresist 110 layer so that sublimationparticles may selectively pass through.

Here, the photoresist 110 is formed on the surface of the pattern unitbase material 130, and the injection and separation step herein is aprocess of selectively separating the photoresist 110 from the surfaceof the pattern unit base material 130. This process makes it possible toform a pattern unit 120 according to the shape of a removed photoresist110 by selectively removing the photoresist 110.

On the other hand, FIG. 6 is an experimental example showing a resultaccording to the process of FIG. 5, and FIG. 6(a) is a view showing awafer before ashing, and FIG. 6(b) is a view showing the wafer afterashing. It can be confirmed that although the surface of the patternunit base material 130 is covered with a photoresist 110 before ashingas shown in FIG. 6(a), the photoresist 110 is separated according to theshape of the mask 140 after ashing as shown in FIG. 6(b).

Hereinafter, the ‘high-speed particle beam generation step’ will bedescribed in detail.

Before describing the ‘high-speed particle beam generation step’ indetail, a ‘nozzle for generating a high-speed particle beam’ used in the‘high-speed particle beam generation step’ will be described first.

FIGS. 7 and 8 are cross-sectional views schematically showing a nozzlefor generating a high-speed particle beam according to an embodiment ofthe present invention.

A nozzle for generating a high-speed particle beam according to anembodiment of the present invention is configured to include an orifice12 provided in a nozzle throat 11 and a dilating portion extended fromthe outlet of the nozzle throat 11.

First, the orifice 12 reduces the cross-sectional area of the nozzlethroat 11 to a microscopic hole by adjusting the opening and closingcross-sectional area of the nozzle throat 11. A particle generation gas(or a mixture gas of a particle generation gas and a carrier gas)passing through the orifice 12 rapidly expands and generates nuclei of anano-size.

In addition, although it is described that the orifice 12 is provided inthe nozzle throat 11, since the nozzle throat 11 herein means a portionwhere the cross-sectional area is narrowest in the nozzle 10, a case ofcombining only the orifice 12 at the inlet side of the dilating portionis also included. That is, the orifice 12 itself may be regarded as anozzle throat 11.

On the other hand, in the case of a nozzle of a device for generatingparticles according to the prior art, a process of cooling down theparticle generation gas should be necessarily included for generation ofnuclei, whereas in the case of the nozzle 10 according to the presentinvention, generation of nuclei can be induced at a room temperaturewithout a separate cooling device by providing an orifice 12 having amicroscopic hole to rapidly expand the particle generation gas. Inaddition, and it may be also possible to generate nuclei of a uniformsize as the particle generation gas rapidly expands.

In addition, the orifice 12 may be formed in a shape of an aperturecapable of adjusting the size of the microscopic hole, as well as in ashape having a microscopic hole of an invariable size, and, on the otherhand, a method of adjusting the size of the microscopic hole byproviding the orifice 12 mounted in the nozzle 10 in a replaceable formmay also be considered.

In addition, the nozzle for generating a high-speed particle beamaccording to the present invention includes a dilating portion providedat the outlet side of the nozzle throat 11 or the outlet side of theorifice 12. The dilating portion is formed in a shape increasing thecross-sectional area toward the outlet side, unlike the particlegeneration nozzle of the prior art. The particle generation nozzle ofthe prior art is formed in a shape repeatedly increasing and decreasingthe size of the cross-sectional area for growth of particles.

More specifically, the dilating portion is configured to include a firstdilating portion 14 and a second dilating portion 15 respectively havinga dilation angle different from the other.

The first dilating portion 14 preferably has a dilation angle θ₁ of 0°to 30°, and as growth of nuclei is accomplished while the particlegeneration gas passes through a first dilating portion 14. The firstdilating portion 14 is formed to have a comparatively gentle dilationangle θ₁ compared with the second dilating portion 15 and provides asufficient time for the nuclei to grow.

Although the first dilating portion 14 is formed to be comparativelylong at a comparatively gentle dilation angle θ₁ and induces growth ofnuclei, it invites reduction of flowing speed since an effective area isreduced as the boundary layer is increased. Accordingly, the seconddilating portion 15 capable of obtaining an additional acceleratingforce is installed to compensate the reduction of speed.

An average dilation angle θ₂ of the second dilating portion 15 ispreferable a dilation angle θ₂ increased by 10° to 45° compared with thedilation angle θ₁ of the first dilating portion 14. Since the seconddilating portion 15 is formed to have an acute dilation angle comparedwith the first dilating portion 14 and forms a high area ratio betweenthe inlet and the outlet, the particles are sufficiently accelerated. Onthe other hand, since the second dilating portion 15 does not have asingle dilation angle unlike the first dilating portion 14 and a thirddilating portion, the angle is expressed as an average angle.

If the dilation angle at the connection portion of the second dilatingportion 15 is changed significantly in steps when the second dilatingportion 15 is extended from the first dilating portion 14, an internalshock wave will be generated. Accordingly, the second dilating portion15 is preferably formed in a shape having curves. Further specifically,the connection portion for connecting the second dilating portion 15 tothe first dilating portion 14 is formed to have a dilation angle thesame as the dilation angle θ₁ of the outlet side of the first dilatingportion 14, and the connection portion is formed to gradually increasethe dilation angle toward the center of the second dilating portion 15to form an acute inclination angle near the center and decrease thedilation angle from the center toward the outlet side of the seconddilating portion 15 so that generation of the internal shock wave may beprevented.

Although it may be considered that the dilating portion of the nozzlefor generating a high-speed particle beam according to an embodiment ofthe present invention is configured to include the first dilatingportion 14 and the second dilating portion 15 as described above, on theother hand, it may be considered to further include a third dilatingportion 16.

The third dilating portion 16 is connected to the outlet of the seconddilating portion 15 and forms a final outlet of the dilating portion.The third dilating portion 16 performs a function of adjusting aseparation point of internal flow inside the nozzle 10.

It is preferable that the third dilating portion 16 has a dilation angleθ₃ increased by 10° to 45° compared with the dilation angle θ₂ of thesecond dilating portion 15 and lower than 90° in maximum.

If back pressure at the rear end of the nozzle 10 is low, a flow fieldmay additionally grow since a separation point goes farther from thenozzle throat 11, and thus it is preferable to form the third dilatingportion 16 to induce the separation point to be positioned at the endportion of the dilating portion while securing a sufficient length atthe same time. It is since that washing efficiency can be increasedgreatly by forming the high-speed core (isentropic core) outside thenozzle 10.

On the other hand, if the back pressure at the rear end of the nozzle 10is formed to be high, it may be regarded that the flow field has alreadygrown sufficiently since the separation point comes closer to the nozzlethroat 11, and thus it is preferable to expose the high-speed core atthe outside of the nozzle 10 by reducing the length of the thirddilating portion 16.

Meanwhile, the outer surface of the nozzle 10 is preferably wrapped witha heat insulation unit 18. The heat insulation unit 18 is configured ofan external insulation tube and an insulating material filled therein.The heat insulation unit 18 accelerates growth of particles bymaintaining thermal resistance of the nozzle 10 and, at the same time,provides mechanical strength by forming an outer wall so that the nozzle10 may endure a high pressure gas. In addition, it is preferable thatthey are formed in one piece to wrap the whole side surface of thenozzle 10.

Meanwhile, FIG. 9 is a conceptual view showing a proximity relationbetween a nozzle for generating a high-speed particle beam according toan embodiment of the present invention and an object 1.

FIG. 9(a) is a view showing a positional relation between the outletsurface of the nozzle 10 and the object 1 of a general case, and FIG.9(b) is a view showing the outlet surface of the nozzle obliquely cut toapproach the nozzle to the object 1 further closer.

As shown in FIG. 9(a), the nozzle 10 generally performs an ashing workwhile being slanted at a predetermined angle. In this case, there is aproblem in that ashing efficiency is lowered since the outlet of thenozzle 10 cannot fully approach the object 1 due to the characteristicof a cylindrical shape.

Accordingly, in order to solve this problem, it is preferable to providethe outlet surface of the nozzle 10 in a form obliquely cut as shown inFIG. 9(b) so as to correspond to a working angle of the nozzle 10. Thecutting angle θ₄ of the shape cut as described above is preferablydetermined within a range of 20° to 90° with respect to the nozzle axis19.

A nozzle for generating a high-speed particle beam according to anembodiment of the present invention has been described above.Hereinafter, a dry separation apparatus including such a nozzle 10 willbe described.

FIG. 10 is a view showing major parts configuring a dry separationapparatus according to an embodiment of the present invention.

A dry separation apparatus according to the present invention may bedivided into i) a case of using a mixture of a particle generation gasand a carrier gas and ii) a case of using only a particle generationgas.

First, i) in the case of using a mixture of a particle generation gasand a carrier gas, the device is configured to include a gas storageunit including a particle generation gas storage unit 40 and a carriergas storage unit 50, a mixing chamber 30, a pressure controller 20 and anozzle 10 as shown in FIG. 1.

In addition, ii) in the case of using only a particle generation gas,the device does not include the carrier gas storage unit 50 and a mixingunit.

In the case of using a mixture of a particle generation gas and acarrier gas, a particle generation gas storage unit 40 and a carrier gasstorage unit 50 are connected to a mixing chamber 30. It is preferablethat carbon dioxide is used as a particle generation gas as describedabove, and nitrogen or helium is used as a carrier gas. The mixingchamber 30 performs a function of sufficiently mixing the particlegeneration gas and the carrier gas and, at the same time, adjusting amixing ratio. It is preferable that the mixing ratio is adjusted to forma carbon dioxide mixture gas by mixing the carrier gas with the particlegeneration gas to occupy 10 to 99% of the total volume of the mixture.

The mixture gas mixed in the mixing chamber 30 flows into a pressurecontroller 20. The pressure controller 20 controls pressure forsupplying the mixture gas to the nozzle 10.

On the other hand, in the case of using only a particle generation gasformed of carbon dioxide, it may be considered to supply the particlegeneration gas to the pressure controller 20 by directly connecting theparticle generation gas storage unit 40 to the pressure controller 20without passing through the mixing chamber 30. Hereinafter, a particlegeneration gas of the case using only a particle generation gas will bereferred to as a pure particle generation gas as a concept contrastingto the mixture gas.

In addition, it is preferable that output pressure at the pressurecontroller 20 is formed within a range of i) 5 to 120 bar in the case ofthe mixture gas and ii) 5 to 60 bar in the case of the pure particlegeneration gas, considering the size and injection speed of thegenerated sublimation particles.

The mixture gas or the pure particle generation gas passing through thepressure controller 20 is supplied to the inlet of the nozzle 10.

The mixture gas or the pure particle generation gas supplied to theinlet of the nozzle 10 sequentially passes through the orifice 12, thefirst dilating portion 14 and the second dilating portion 15 asdescribed above, and the sublimation nano-particles are injected ontothe object 1. Since the detailed internal structure of the nozzle 10 isdescribed above, overlapped descriptions will be omitted.

Hereinafter, a ‘high-speed particle beam generation step’ according toan embodiment of the present invention will be described.

A high-speed particle beam generation step according to an embodiment ofthe present invention is generating high-speed uniform nanoparticles bypassing a particle generation gas formed of carbon dioxide through thenozzle 10. Here, the particle generation gas may be mixed with thecarrier gas and supplied to the nozzle of a mixture gas or may besupplied in the form of a pure particle generation gas.

First, when the particle generation gas is supplied in the form of amixture gas, it is preferable to sequentially include a mixing step offorming the mixture gas by mixing the particle generation gas and thecarrier gas and a pressure control step of adjusting pressure of themixture gas passing through the mixing step.

Here, the carrier gas is formed of nitrogen or helium, and it ispreferable to control the pressure of the mixture gas passing throughthe pressure control step to 5 to 120 bar and flow the mixture gas intothe nozzle 10.

After performing the pressure control step, the nucleus generation stepof generating nuclei is performed as the particle generation gas rapidlyexpands while passing through an orifice 12 provided in a nozzle throat11 of the nozzle 10.

Then, after performing the nucleus generation step, the particlegeneration step of generating sublimation particles is performed asgrowth of nuclei is accomplished while the particle generation gaspasses through a first dilating portion 14 extended from the outlet ofthe nozzle throat 11 and having a dilation angle θ₁ of 0° to 30°.

Then, after performing the particle generation step, the particleacceleration step of offsetting growth of a boundary layer andincreasing the speed of injecting the sublimation particles is performedas the particle generation gas passes through the second dilatingportion 15 extended from the outlet of the first dilating portion 14 andhaving an average dilation angle θ₂ increased by 10° to 45° comparedwith the dilation angle θ₁ of the first dilating portion 14.

It is preferable to further include, after performing the particleacceleration step, the flow control step of forming a high-speed core ofthe sublimation particles outside the nozzle 10 as the particlegeneration gas passes through the third dilating portion 16 extendedfrom the outlet of the second dilating portion 15 and having a dilationangle θ₃ increased by 10° to 45° compared with the average dilationangle θ₂ of the second dilating portion 15 and lower than 90° inmaximum.

On the other hand, in the case of supplying only the pure particlegeneration gas, a pressure control step of adjusting the pressure of theparticle generation gas is performed without performing the mixing step.

Here, it is preferable that pressure of the particle generation gaspassing through the pressure control step is controlled to 5 to 60 barto flow the particle generation gas into the nozzle 10.

The steps following thereafter are the same as the nucleus generationstep, the particle generation step, the particle acceleration step andthe flow control step.

The positional relations used to describe a preferred embodiment of thepresent invention are described focusing on the accompanying drawings,and the positional relations may be changed according to the aspect ofan embodiment.

In addition, unless otherwise defined, all terms used in the presentinvention, including technical or scientific terms, have the samemeanings as those generally understood by those with ordinary knowledgein the field of art to which the present invention belongs. In addition,the terms should not be interpreted to have ideal or excessively formalmeanings unless clearly defined in the present application.

Although the preferred embodiment of the present invention has beendescribed above, it should be regarded that embodiments simplyaggregating prior arts with the present invention or simply modifyingthe present invention, as well as the present invention, also fallwithin the scope of the present invention.

The invention claimed is:
 1. A dry separation method for ashing aphotoresist, the method comprising: a high-speed particle beamgeneration step of generating sublimation particles; and an injectionand separation step of separating the photoresist by injecting thesublimation particles on the photoresist, wherein the high-speedparticle beam generation step is characterized in that a particlegeneration gas passing through a nozzle is injected onto an object,wherein the nozzle includes a first dilating portion and a seconddilating portion, and an average dilation angle of the second dilatingportion is wider than a dilation angle of the first dilating portion,and wherein the injection and separation step comprises: a nucleusgeneration step of generating nuclei at room temperatures without anextra cooling device by passing the particle generation gas through anorifice and rapidly expanding the particle generation gas, wherein theorifice is provided in a nozzle throat of the nozzle to reduce across-sectional area of the nozzle throat to a microscopic hole; aparticle generation step of generating the sublimation particles bygrowing the nuclei while passing the particle generation gas through thefirst dilating portion after performing the nucleus generation step,wherein the first dilating portion is extended from an outlet of thenozzle throat so that a cross-sectional area of the first dilatingportion gradually widens; and a particle acceleration step of increasingspeed of injecting the sublimation particles by passing the particlegeneration gas through the second dilating portion after performing theparticle generation step, wherein the second dilating portion isextended from an outlet of the first dilating portion so that across-sectional area of the second dilating portion gradually widens,and the second dilating portion has the average dilation angle widerthan the dilation angle of the first dilating portion.
 2. The methodaccording to claim 1, wherein the photoresist is formed on a surface ofa wafer, and a predetermined area of the photoresist is separated fromthe wafer by injecting the sublimation particles on the photoresist. 3.The method according to claim 1, wherein the photoresist is formed on asurface of a pattern unit formed on a wafer, and the photoresist isseparated from the pattern unit by injecting the sublimationnanoparticles on the photoresist.
 4. The method according to claim 1,wherein the photoresist is formed on a surface of a pattern unit basematerial formed on a wafer, and the photoresist is separated from thepattern unit base material by injecting the sublimation nanoparticles onthe photoresist.
 5. The method according to claim 1, wherein thephotoresist is formed on a surface of a pattern unit base materialformed on a wafer, and a predetermined area of the photoresist isselectively separated from the pattern unit base material by injectingthe sublimation nanoparticles on the photoresist.
 6. The methodaccording to claim 5, wherein the predetermined area of the photoresistis selectively separated from the pattern unit base material byproviding a mask on a top of the photoresist.
 7. The method according toclaim 1, wherein the particle generation gas is formed of carbondioxide, and the first dilating portion has a dilation angle of 0° to30°, whereas the second dilating portion has an average dilation anglewhich is 10° to 45° more than the dilation angle of the first dilatingportion.
 8. The method according to claim 7, wherein the high-speedparticle beam generation step further includes, after performing theparticle acceleration step, a flow control step of forming a high-speedcore of the sublimation particles outside the nozzle by passing theparticle generation gas through a third dilating portion, wherein thethird dilating portion is extended from an outlet of the second dilatingportion and has a dilation angle which is 10° to 45° more than theaverage dilation angle of the second dilating portion and lower than 90°in maximum.